Definition
In Roman and civil law, a person born of promiscuous or illicit sexual union — a bastard. The term specifically denotes a child whose father is either unknown or legally unrecognized, born outside of any lawful marriage or recognized union. Under Roman law, a spurius was also described as vulgo quaesitus or vulgo conceptus, meaning one "sought from the crowd" — a child whose paternity could not be assigned to a specific man. The Greek equivalent, apatōr, carries the same force: literally "without a father."
The spurius occupied a defined but disadvantaged position in Roman law. Such a child took the status of the mother rather than the father, could not inherit through intestate succession on the paternal side, and was excluded from rights that depended on legitimate filiation, including claims to patria potestas and agnatic kinship.
Common Language
Modern common usage (Wiktionary): "Spurious" in modern English means false, counterfeit, or not genuine — as in a spurious argument or spurious document.
Historical common usage (Webster's 1913): Webster's defines "spurious" as "not proceeding from the right source, or from the source pretended; not genuine; counterfeit; false; adulterate." Webster's also notes the secondary sense: "of illegitimate birth; bastard."
The gap between common and legal meaning is significant and runs in opposite directions. Modern English speakers encounter "spurious" almost exclusively in its sense of falseness or inauthenticity — a spurious claim is a bogus one. The legal Latin noun spurius, by contrast, is a status designation for a person, not a quality attached to a document or argument. The shared root is the concept of doubtful origin, but in legal sources the term is a term of personal status, not of epistemic or evidentiary critique. A researcher encountering spurius in a civil law text should read it as a technical classification of a person's birth status, not as a general term of condemnation.
Common Confusion
Spurius is sometimes loosely conflated with other Latin terms for illegitimate children — particularly nothus and bastardus. These are not synonyms. A nothus was born of a free woman and a slave, or of parents whose union, while not lawful marriage, was at least identifiable. A spurius was specifically the product of indiscriminate or promiscuous intercourse, with paternity unknown or unknowable. Bastardus is the broader medieval and common law term that absorbed these distinctions without preserving them. Researchers working across civil law and common law sources must not assume these terms are interchangeable; the distinctions affected inheritance rights, claims to citizenship, and status transmission differently in each framework.
Why It Matters in Research
Spurius is a term of Roman and civil law with limited direct reception in English common law. Researchers in common law sources will rarely encounter it as operative terminology; when they do, it signals a civilian-trained author or a text drawing on Roman sources. The term matters most in: (1) continental European legal materials translated or cited in English texts; (2) ecclesiastical law sources, where questions of legitimacy were within church jurisdiction and civilian learning was applied; (3) Scottish law, which retained a stronger civilian inheritance and where distinctions among categories of illegitimacy carried practical weight longer than in England; and (4) early American treatises drawing on civil law foundations for family law doctrine.
The key research trap is anachronism. A modern reader seeing "spurious" in a legal text may read it as an adjective meaning fraudulent or counterfeit. In older legal and civil law sources, it is most likely functioning as a noun or noun-adjective of personal status. Context — particularly the presence of other civil law terminology or discussion of inheritance and filiation — should resolve ambiguity.
The shift in English usage away from the personal-status meaning and toward the epistemological meaning was largely complete by the nineteenth century. Historical common law dictionaries rarely include spurius at all, which itself reflects that the term was not naturalized into English legal vocabulary and remained a Latinism of learned or civilian discourse.
Historical Dictionary Support
The three source dictionaries are in close agreement on the core definition, differing only in the depth of surrounding context. Black's (both editions) provides a compact definition: a bastard, the offspring of promiscuous cohabitation. Burrill offers substantially more: the Roman law synonyms (vulgo quaesitus, vulgo conceptus), the Greek equivalent (apatōr), and institutional references to Justinian's Institutes (1.10.12) and Bracton (fol. 63). The inclusion of Bracton is notable — it places the term at the intersection of Roman civilian learning and early English jurisprudence, suggesting that Bracton imported the concept even if English common law ultimately developed its own vocabulary for illegitimacy.
What the historical dictionaries do not address is the functional legal consequence of spurius status — specifically, the inheritance disabilities and the rule that a spurius followed the condition of the mother. Researchers needing that operational content must look beyond dictionary entries to the institutional sources Burrill cites.
Jurisdictional Note
Spurius as a technical term of art belongs to Roman and civil law systems. Its practical significance in historical legal research is greatest in jurisdictions with substantial civilian inheritance — Scotland, Louisiana, Quebec, and jurisdictions whose private law drew on Roman Dutch or Spanish sources. In English common law jurisdictions, the concept was subsumed under the general category of bastardy without preserving Roman subcategories.